Bittrex has involved in IEO. Their IEO was canceled the day before due to significant changes in the business status of the project in question, RAID. Still, we know for sure that Bittrex is on the lookout for more IEO opportunities. I would pay attention to it.

Anyway, check out ICO Widgets (https://icowidgets.com) or Coinspeaker (https://www.coinspeaker.com/ieo/).